The present invention relates to a multicolor printed product with a base which carries on top of one another a plurality of color mosaic images of a color set, especially a blue, yellow, red, and possibly black, color image.
It is known to print images by applying to a base a plurality of colors of a color set, namely blue (cyan), yellow, red (magenta) and possibly black (depth), in a corresponding distribution. For instance, each color image may consist of a multitude of mosaic dots. The color distribution in each individual image depends on the magnitude of the individual mosaic dots. The light color of the base, especially a base consisting of white paper, constitutes the lighter zones of the image in that no dots or only small mosaic dots are printed thereat.
When printing plates for the various color images are to be manufactured for use in offset printing, one proceeds by making color extracts from the original in the form of black-and-white positive films. This is accomplished by photographing the original with the aid of interposed complementary color filters. The resulting positive films can be directly provided with the mosaic; however, they can also be produced as halftone color extracts, from which the mosaic positive films are then produced. These mosaic positive films serve for the exposure of the offset printing plates in such a manner that the black parts of the positive film later serve for the color transfer. Reference may be had to pages 189-194 of "The Printing Industry" by Victor Straus, published by Printing Industries of America Inc., Washington, D.C. 20015 (Library of Congress Catalog Card Number 67-26209). Reference may also be had to pages 114 to 144 of the German-language publication entitled "Offsettechnik" by Ing. Hermann Rittweger (Third Edition published by Fachschriften-Verlag, Fellbach near Stuttgart, Federal Republic Germany). It is also known to expose the offset printing plates by means of negative films. Similar methods are in existence not only for surface printing, but also for relief and intaglio printing.
It is further known to add a pearl luster pigment to printing dyes in order to give these dyes a certain luster. However, the printed products manufactured in this manner leave much to be desired in terms of brilliancy of the composite image.